function popup(link, nomform, w, h, para)
{
	var top=(screen.height-h)/8;
	var left=(screen.width-w)/8;

	var fen=window.open(link, nomform, 'width=' +w+ ',height=' +h+ ',left=' +left+ ',top=' +top+ para);
	if (self.focus) fen.focus();

	return fen;
}